Scientists in London say that they've been able to create a human embryo using DNA from one man and two women. The science involves the energy source of cells called the mitochondria.
In the lab, scientists took an embryo created from one man and one woman with defective mitochondria. Then they transplanted the nucleus of that egg into a healthy woman's donor egg. Since a very small amount of material is actually "transplanted," researchers do not consider the embryo to have three parents. The embryos were destroyed within a week of the transplant.
The hope is that someday this procedure could be used in babies conceived through in-vitro fertilization to prevent epilepsy, muscle problems, mental retardation, and even heart and brain disorders.